A summary of research projects and publications dealing with mosquitoes, wetlands and urban ecology (as well as other Medical Entomology activities) by Dr Cameron Webb (University of Sydney & NSW Health Pathology)

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My PhD student Jayne Hanford has been super busy this year. Not much more than a year into her candidature and she has already locked away a summer of research and has been presenting her findings at conferences here in Australia as well as overseas.

Her research is focused on understanding the links between wetland vegetation, aquatic biodiversity and mosquito populations. Better understanding of these links will assist management strategies that minimise actual and potential pest and public health risks associated with mosquitoes and urban wetlands.

Our abstract for the conference is below:

Is the Biodiversity Value of Constructed Wetlands Linked to their Potential Mosquito-Related Public Health Risks?

Jayne Hanford1, Cameron Webb2, Dieter Hochuli1

1School of Life and Environmental Sciences, The University of Sydney, Australia; 2Department of Medical Entomology, Westmead Hospital and The University of Sydney, Westmead, Australia

Stormwater treatment wetlands constructed in cities can enhance the sustainability of urban biodiversity by providing wildlife refuge areas and habitat connectivity. However, the creation of wetlands for stormwater infrastructure can increase risks to public health and wellbeing by proliferating nuisance-biting and pathogen-transmitting mosquitoes. In severe cases, this proliferation can erode goodwill in the community for creating and protecting valuable wetland systems. We compared mosquito assemblages at 24 natural and constructed urban wetlands in the greater Sydney region, Australia. Our aim was to determine if stormwater wetlands constructed with the goal to support high biodiversity value also had reduced associated mosquito risks. Wetlands were located across a gradient of urbanisation determined by surrounding human population density, and included sites with different aquatic and riparian habitat complexity and availability. Adult and larval mosquitoes and aquatic macroinvertebrates were sampled on two occasions through summer and autumn. Aquatic macroinvertebrates were used to derive health indices, as well as being a relative measure of aquatic diversity. Diversity of adult mosquito species was high, and abundance varied greatly between wetlands. Macroinvertebrate assemblages were also highly variable between sites. Wetlands with greater habitat complexity had lower adult mosquito abundance and greater mosquito species diversity, compared to stormwater-specific wetlands with minimal available habitat. As expected, mosquito assemblages did not respond to urbanisation and aquatic macroinvertebrate assemblages per se, but appeared to respond to a complex suite of coarse and fine-scale features that may affect a wetland’s biodiversity value. Effectively integrating wetlands into cities requires balancing their design for water infrastructure purposes, biodiversity resources and public health and wellbeing requirements. Understanding the risks as well as the benefits will enhance the value of constructed urban wetlands in sustainable cities while minimising public health risks posed by mosquitoes.

Jayne will be speaking in the “The next generation of wetland science: ecosystems, applications, and engineering” session in the Nanhu Room 1520-1530 on Wednesday 21 September.

You can keep an eye on whats happening in China by following Jayne on Twitter and checking the hashtag #IWC10

The Society for Wetland Scientists Annual Conference held in Corpus Christi, Texas, USA back in May included a paper by Jayne titled “Risky Wetlands? Conflicts between biodiversity value and public health” and prompted some great feedback and discussion among wetland scientists at the meeting. It was a successful trip and a timely reminder that I must get to one of the SWS meetings sometime soon, perhaps Puerto Rico?

For a few months now I’ve been thinking through some future options for the blog and my science communications activities. I’ve been toying around with starting a podcast or video blog about my work in local wetlands.

A year or so ago I had the chance to see Karen McKee (aka The Scientist Videographer) talk about social media and the ways she uses video as a critical component of her community engagement and communications. Since I’m already using Instagram to connect followers with my various wetland sites and mosquito studies (as well as other things), I’ve thought video could be a way to go.

I’m an advocate for mosquito control to be part of overall wetland management. I think I’m sometimes seen as the enemy of wetland and wildlife conservation, not surprising given the perception of mosquito control still influenced by the DDT debate. As we push for the construction and rehabilitation of urban wetlands, the pest and public health risks associated with mosquito populations do need to be considered by local authorities.

I’m often arguing that ecologically sustainable mosquito management is actually critical to wetland conservation. If you’re encouraging the community to visit your wetlands, what happens when they’re chased away by mosquitoes? What about the community living around the wetland? Will nuisance-biting erode the good will of the community for wetland conservation?

You can watch my video, “Why is mosquito management important in our local wetlands?”, at YouTube or below:

You can check out some of my other posts of wetlands, mosquitoes and social media below:

You have no idea how badly I wanted to jump down into the thick black mud.

I don’t remember much about primary school but I do have strong recollections of an assignment on the importance of mangroves to the ecology of the Parramatta River. Perhaps not the assignment itself, but I do remember Mum and Dad taking me down to the river and I drew some pictures of the twists and turns of branches and trunks and the finger-like pneumatophores punching up through the thick dark grey mud. It may only have been 10 minutes drive from home in Western Sydney but it was a glimpse into a world so strange and alluring, how could it not have made an impact on me?

I remember the great disappointment of my parent’s stern words keeping me from jumping down below the high water mark and into the mud. The same feelings of frustration and disappointment when stopped from doing other fun things like playing in stormwater drains, letting off firecrackers or swimming in rips!

Mangroves don’t just attract the attention of young environmental scientists. Exploiting a unique place between the land and sea, mangroves have intrigued and fascinated many before me with the first descriptions, by Greek mariners, thought to date back to 325BC. What were these plants that seemed to defy logic, growing half submerged in salty water?

Almost thirty years after my primary school assignment, with sandshoes replaced by gumboots, that childhood disappointment of adventure squashed is now matched by the realisation that mangroves aren’t perfect. In fact, they’re a threat to some of the other plants and animals found in our local local estuaries.

Now I spend most of my summer coated in that same dark grey mud, covered in mosquito bites and thinking about how important mangrove management will be for the future of our coastal wetlands.

More than mangroves

There is little doubt mangroves are an ecologically important habitat. They provide a home for a wide range of creatures, from bacteria to birds. Rich in nutrients and hiding places, mangroves are perfect nurseries for fish and crustaceans. Bird and bats and rodents and reptiles all find a home here too.

Make no mistake, mangroves are important. Thing is, it is also important to also remember that estuarine wetlands are more than just mangroves.

When we talk about estuarine wetlands, we’re grouping together a number of habitats that include seagrass, saltmarsh, sedgelands and mudflats as well as mangroves. Each of these habitats play an important role in the functioning of the estuary as a whole but they each, individually, provide something specific to the wildlife that utilise the wetlands.

One of the key threats facing saltmarshes is a native plant. A native estuarine wetland plant. Mangroves.

The encroachment of mangroves into saltmashes is a serious problem. This is happening in many parts of the world. It is a strange situation in which one native plant is taking over another and with these ecological shifts, there are knock-on effects to other components of the wetland ecosystem. Most importantly, nesting and feeding shorebirds.

Are mangroves really a threat?

The mangroves are just doing what mangroves do. The reason they’re threatening saltmarshes is due to our modification of local environments.

Urban runoff reduces the salinity of these wetlands and this reduced salinity not only removes the ecological advantages of salt-tolerent saltmarsh plants, such as Sarcocornia quinqueflora and Sporobolus virginicus, but it helps mangrove seeds and seedlings survive the otherwise harsh environmental conditions of saltmarshes. Lower the salinity, increase the invasive potential of mangroves.

Frequent dryness and highly salty conditions are a saltmarsh’s best defense against invading mangroves.

Filling in wetlands and the construction of seawalls, roadways and other infrastructure give saltmarshes little refuge or respite from these threats. While mangroves encroach from the sea, there is nowhere for saltmarshes to migrate to when dealing with sea level rise.

They’re cornered and under attack but even where the plants are persisting, the quality of habitat they provide for local wildlife is slowly degraded by colonising mangrove seedlings.

There are many waterbirds that use our local estuaries that are under threat. Saltmarshes are great habitats for migratory shorebirds. There are plentiful resources in the form of insects and other invertebrates within the sediments. The birds can nest on the marsh and as they can see all around, predators are easy to spot. They feel safe.

For many of these birds, the encroachment of mangroves into mudflats and saltmarshes is a problem. Its a problem for their foraging and nesting. Once mangrove seedlings start popping up on the middle of the saltmarsh, all those advantages of a wide open habitat in which predators are easy to spot are lost.

Imagine you’re a black-winged stilt. You’re trying to find a safe place to nest. A perfect place would be a raised area of saltmarsh surrounded by water. A dead flat saltmarsh with clear lines of sight for dozens of meters around. You’ll be able to see an approaching predator (like a fox or a feral cat) from far enough way to escape with plenty of time to spare. Now, stick a few mangrove seedlings here and there. They start to obscure your view. They’ll give sneaky predators a place to hide. Even if there are not predators about, you’ll probably get nervous. You’ll probably spend more time thinking about the threat of predators and less time foraging for food.

As mangroves move in, the birds will leave. Long before the saltmarsh is over run by mangroves, out-competed by the shade of establishing young mangroves, the quality of the habitat for many shorebirds will have already been lost. There may be some plants remaining but the ecological role of the habitat is gone.

Do historic paintings provide conflicting evidence to the commonly held view that mangroves have always been present along the Parramatta River? (Parramatta River, c. 1837, Conrad Martens (1801-78) via Australian Art Auctions)

Painting the picture of change in the local wetlands

How can we predict what will happen in the future if we haven’t learned from the past?

Tracking change in these wetlands is important. The use of photography has played an important role in tracking environmental change for a long time. Aerial photography and satellite imagery have helped reveal dramatic changes in vegetation associated with Australia’s coastal wetlands. This analysis has demonstrated the encroachment of mangroves into saltmarshes and this encroachment is considered a key threatening process of this endangered ecological community.

How can we track the encroachment of mangroves? While technology has helped reveal current changes in mangrove encroachment, other uses of imagery can explore relatively recent “urban myths” about historic mangrove distribution.

Thinking back to that school assignment, I remember being told how important mangroves were to the local environment. We we taught that, here in Sydney, that mangroves were always part of the Parramatta River estuary, that they have alwasy been a critical component of the river’s ecology. Was this really the case?

“These historical sources indicate that in the 19th century extensive mudflats and saltmarsh communities dominated the inter-tidal zone, with mangroves more limited to creek fringes and some patches in bays for much of the period. In the upper river from Subiaco Creek to Parramatta, there is no evidence for the presence of mangroves until the 1870s. Following settlement and increased sedimentation, inter-tidal mudflats expanded, mangroves colonised up river and out onto mudflats in bays in the latter part of the 19th century, followed by expansion into saltmarsh in the 20th century.”

It is only relatively recently that mangroves have really flourished along the river.

There is absolutely no doubt they were always present, tucked away in the tiny bays and inlets of what became known as Sydney Harbour but it was the mudflats and saltmarshes that dominated much of the estuary. These habitats, no doubt, provided a rich and productive habitat for shorebirds and other wildlife.

So, where to from here?

Globally, mangroves are a critical component of wetland ecosystems. There is little doubt of that, and little doubt that in many parts of the world, even here in Australia, they are under threat. But so is saltmarsh and, saltmarsh is far less likely to be given the chance to demonstrate the resilience that mangroves will to continued changed environmental conditions results from a rising sea level and surging urbanisation.

Not just saltmarsh but mudlfats too.

Coastal authorities are increasingly aware of the need to balance protection of mangrove forests and the benefits they provide but also the conservation of saltmarsh and mudflats that are so critical to shorebirds.

The reality is, there will need to be a program of mangrove culling to sustain conservation of saltmarsh habitat. You need a permit to remove mangrove seedlings but a seasonal program of removal would be greatly beneficial in stopped the spread of mangroves into saltmarsh habitats. Local authorities are incorporating mangrove removal programs in their local wetland rehabilitation programs.

Removing young seedlings is easy, you can pull them straight out of the wet mud. Wouldn’t take much to organise a team of volunteers to move through the local saltmarsh removing seedlings. Perhaps in Autumn when the migratory shorebirds have left and the mosquito populations aren’t so bad?

The idea that native vegetation should be actively removed from habitats sounds at odds with environmental conservation. However, we need to maintain our wetlands for our future generations and the next generations of birds, and fish and crustaceans that rely on them now where few other opportunities exist.

2 February is World Wetlands Day. Please get out into your local wetlands, or at least make a pledge to visit your nearby wetlands sometime soon.

Finally, check out one of the most extensive resources on urban wetland management, including estuarine wetlands, via the free eBook produced by the Sydney Olympic Park Authority titled “Workbook for Managing Urban Wetlands in Australia“. Read a brief article on our analysis of the use of this resource in the latest issue of Wetlands Australia, see “Insights from the use of an online wetland management resource” by Webb and Paul (pages 26-27).

What are you doing for World Wetlands Day? Join the conversation on Twitter!

Want to learn more about the amazing world of Australian mosquitoes? Check out “A Field Guide to Mosquitoes of Australia” out now through CSIRO Publishing. Over 200 pages containing a pictorial guide to almost 100 different mosquitoes along with tips on beating their bite and protecting your family from the health risks of mosquitoes. You can order online or through your favourite local bookstore or online retailer.

Mosquitoes can be more than a nuisance. They pose health risks but could also erode the good will of the community for wetland rehabilitation projects. Wetland rehabilitation needs mosquito control.

It’s a warm February evening. A small and anxious group of residents have gathered in a local community hall to discuss the implications of a local wetland rehabilitation project. Some are angry. One of the first questions comes from an elderly gentleman. Close to tears, he explains how his grandchildren no longer visit due to the plagues of mosquitoes that engulf his property day and night. “What are you guys going to do about it?” he pleads.

I learnt a valuable lesson that night. Trying to explain the best mosquito repellent to use doesn’t go down too well when an audience is facing some significant nuisance-biting impacts around their homes. It doesn’t matter how much DEET is in the repellent, it may well work but is it something you need to wear all day just to get the day to day jobs done around the house? Something more substantial is required and, with hindsight, should have been in place before the first waves of mosquitoes left the local wetlands.

Coastal wetlands are under threat

Sea level rise and climate change is putting pressure on saltmarshes and urbanisation is eating away land that would otherwise accommodate a landward shift in estuarine habitats. There is nowhere for saltmarshes to spread to so they’re destined to be swallowed up by mangroves. While the mangroves are valuable themselves, they don’t provide the same critical habitats required by many of the internationally protected migratory shorebirds that rely on saltmarshes. Saltmarsh habitats could well disappear from much of the east coast in coming decades if sea levels rise as expected and mangroves continue their march landward.

Estuarine wetlands and mosquitoes

Saltmarshes are home to one of our most important pest and vector mosquito species. While it is important to remember that Aedes vigilax is an Australian native animal and just as much a part of our wetland ecosystems as fish and birds, there is little doubt that it can have substantial impacts with regard to nuisance-biting and the transmission of Ross River virus.

Historically, many of the saltmarshes along the east coast were drained or filled to enable increased cattle grazing (although much of it was under the guise of protection from flooding). Tidal flows were cut off with the construction of levee banks and installation of flood gates. Notwithstanding the impacts of grazing, without tidal exchange, the habitats became brackish water to freshwater dominated systems with a dramatic change in vegetation. Saltmarsh and sedgeland vegetation was steadily replaced by reeds and rushes. Invasive plants such as Phragmites quickly took over many of these wetlands.

Bringing back the tides

To combat the degradation of wetlands and impending loss due to climate change, there has been some ambitious wetland rehabilitation projects planned. One of the largest in the southern hemisphere is the Hexham Swamp Rehabilitation Project. Much can be learned from the experience in this wetland just west of Newcastle, NSW, and applied to rehabilitation projects, not only in Australia but overseas as well.

Rehabilitation of Hexham Swamp involved the staged opening of existing floodgates to reinstall tidal flows to an otherwise freshwater system. Many aspects of this project were considered and it is unsurprising that one major issue was the possible impact of mosquitoes. Mosquito populations were something of legend in this area, enough so that there is a “big mosquito” outside the local bowling club affectionately known as “Ossie the Mossie” (coincidently, “Ossie” celebrated her 20th birthday in March 2014).

One of the important considerations when assessing mosquito risk was that there had been a dramatic transformation of the areas surrounding the wetlands in the last 20 years. What was once agricultural land was now residential. This is the same situation right along the east coast of Australia, the rapid urbanisation and swelling residential populations along the coast have put people in the firing line of Aedes vigilax.

The prospect of mosquito control was raised in the early stages of the rehabilitation planning but there was great reluctance from the local authorities to head down that path. The problem is that broad scale mosquito control and ecological rehabilitation are often seen at opposite ends of the wetland management spectrum. I’ve experienced this many times first hand, from scepticism regarding the non-target impacts of biological larvicides to “Apocalypse Now” jokes as helicopters go about routine spraying of local wetlands.

Is there such a thing as “environmentally friendly” mosquito control?

The hangover from the actual and perceived impacts of pesticide use more than 50 years ago is still present in the minds of many responsible for managing local wetlands. I say perceived as the development of environmentally sustainable mosquito control programs over the past two decades may not be appreciated amongst those charged with managing wetlands and wildlife.

I feel we need to continue building the case for the range of mosquito control strategies available for our coastal wetlands. Not only do we need to convince local authorities that mosquito populations can be minimised without adversely impacting the local environment but that mosquito control should be a critical consideration in wetland rehabilitation projects. It also has the potential to reduce mosquito-borne disease.

We know that the direct non-target impacts of Bacillus thuringiensis israelensis and s-methoprene are minimal and there is growing evidence that the indirect impacts on local wildlife due to reduced mosquito populations isn’t a major concern. Well-designed projects can also minimise the frequency of treatments while reducing peaks in mosquito activity.

It seems our coastal bats populations are mostly eating moths, not mosquitoes so there is unlikely to be any significant impact on these bats resulting from reduced food. There is no reason why the judicious use of larvicides can’t knock the top off abundant mosquito populations, reduce the pest impacts on local community and not pose a risk to local wildlife. Perhaps it should be considered a critical component of wetland rehabilitation?

Mosquito control and wetland rehabilitation

In speaking with wetland managers, I try to instil with them the importance of mosquito control. There is a risk that swarms of nuisance biting mosquitoes may erode the good will in the community for wetland rehabilitation. These systems, particularly in the early phases of rehabilitation don’t represent pristine environments and while there may not be a desire to establish ongoing mosquito control programs, some control may prove useful while the wetland comes back into balance with the changed environmental conditions.

Rehabilitation takes time and while there is substantial breakdown of freshwater vegetation it is not going to be ideal for fish and other mosquito predators. It is likely to provide ideal conditions for mosquitoes. Over time, however, fish are likely to increase in both their abundance and penetration into the wetlands and greater tidal flushing will make many of the wetland habitats generally unsuitable for mosquitoes.

Perhaps there is benefit in undertaking control as a show of good will to the local community? After all, engagement with the local community will be critical in the success of wetland rehabilitation projects.

The restoration of tidal flows to Hexham Swamp resulted in an initial increase in the abundance of Aedes vigilax. These increases resulted in substantial nuisance-biting impacts. However, in subsequent seasons, the populations of Aedes vigilax levelled out to comparable levels to those of the surrounding estuarine wetlands. The net result has generally been that the long-term moderate increases in Aedes vigilax populations have been balanced by reductions in Culex annulirostris and Coquilettidia linealis populations as the wetlands shifted from freshwater to saline. The health of the wetlands, as well as the local estuary, is improving.

Mosquito control is only a short-term fix and if the rehabilitation of estuarine wetlands is not carefully planned, there may well be ongoing mosquito impacts. However, reducing any initial impacts will go a long way to ensuring continued engagement of the community with the local wetlands. Cost and the operational considerations may be a barrier for organisations unfamiliar with broadscale mosquito control but these issues can be overcome with the expertise that exists in many parts of the country.

There was lots of love about Entomology 2014 but some of the biggest highlights had nothing to do with the bugs. Here are some non-entomological hits from the conference.

1. Portland, OR.

Host city makes a difference. I know many considerations are taken into account when deciding on a venue but an interesting host city (or region) can really tip the scales. Portland was a great decision. One of the great things about Portland was that it provided many conversation starters. Tips on where to find the best coffee, craft beer and donuts dominated plenty of on- and offline conversations during the course of the meeting (plus a few “field trips” thrown in for good measure).

I’ve seen interesting/new locations boost the numbers of conference attendees for the Australian Entomological Society and Mosquito Control Association of Australia in recent years too.

2. Free public transport

Brilliant. With the meeting attracting over 3,000 people, it wasn’t possible to hold the event at a single venue that also provided accommodation for the bulk of attendees. As everyone was spread out across the city, getting back and forth from the Oregon Convention Center could have been quite tricky. Portland has a great public transport network but, better still, conference registrants received a free pass for travel throughout the course of the meeting! It certainly took the stress out of getting around.

3. Promotion of social media

The Entomological Society of America really needs to be congratulated on the way they’re employed social media as a critical component of their scientific conferences. I’ve been to conferences where social media has been tolerated but rarely encouraged. At this meeting, social media use was integrated into the day-to-day conference experience.

There was promotion of #EntSoc14 before, during and after the meeting. From the registration website to the opening address by David Gammel, social media was embraced and encouraged. Probably the best element was the use of a series of large screens throughout the conference center with a cascade of twitter and instagram posts. There was even a large display in the trade hall! Wonderful idea because it brought the “non-tweeting” conference attendees into the mix. I had a few a few conversations with people who don’t use social media but tracked me down because they’d seen tweets on the screen earlier in the meeting.

An example of the “social media screens” dotted throughout the conference venue (Source: Christie Bahlai ‏@cbahlai)

Having an opportunity to meet in real life many of the wonderful people I’d only ever corresponded with via social media was one fo the highlights of the conference.

Here are the key slides (plus a bonus) from my conference presentation on the use of social media to extend the reach of public health messages:

4. Free WiFi

Whether we like it or not, we’re tethered to work. I learned a valuable lesson this year when I took myself “off the grid” for a few weeks during a holiday break. It took me the best part of a month to catch up. Being able to regularly check in with work emails during a conference (without having to pay exorbitant access rates) really helps. It is also handy chasing up papers referenced in presentations and other resources shared throughout the conference.

I know it is no fun seeing a conference room full of people checking email during someone’s presentation and I personally don’t do it myself. However, there were plenty of places and spaces to sit down and do that outside the presentation rooms.

A picture may well tell a thousand words but what if that picture is tweeted, shared and liked? Could social media help engage the community with local wetlands? Could it assist in crowd sourced tracking of environmental change?

After the fire comes the photos

Using photography to track post-bushfire environmental change is common in Australia where bush fires are a part of life. Scientific publications and technical reports produced across the country have used “before and after” photos to highlight the dramatic change, and equally dramatic recovery, seen in the Australian bush after fire.

How can we incorporate social media in tracking this post-fire recovery? Perhaps it could even play a role in boosting the spirits of the local community seriously impacted by bushfire? The recovery of communities is as important as recovery of the environment. A recent study has highlighted the importance of social networks in the community and perhaps opportunities to share interactions with the environment through social media would provide further opportunities for engagement.

Bushfires are a natural part of the Australian environment and photography plays a key role in reminding us that our vegetation can respond remarkably after even the most intense fires (Source: CSIRO)

The idea is based around members of the community taking photos at set locations with set perspectives and compiling those photographs shared through social media, to create a crowd sourced time lapse animations of post-bush fire recovery (you can read a little more about it here). What makes this so neat is the simplicity. Clear signage and a simple bracket for lining up your camera/phone. The website interface is great too. The team behind the project have provided some detailed instructions that form a great basis for adapting this approach to a local environment (they also point out that this project may not be as simple to implement as you may think…).

An Australian take on crowd sourced “environmental change” photography

Another example of using photography to track environmental change is the Australian Fluker Post project. Similar to the approach by the Nerds for Nature team, this project, coordinated by Dr Martin Fluker at Victoria University, is a “citizen science system designed to allow community members to contribute towards the ongoing care of various natural environments by taking photographs”.

“Fluker Posts” are installed at key locations and members of the community can use their own cameras to take photos and then email them to coordinators. As well as collecting material to assist local land managers, this project may have a more subtle influence on conservation by engaging the community with the local environment. By providing an opportunity for local residents (as well as regular visitors) to track the changes in their local environment, it would be hoped that a connection and care for the local environment would increase. As well as directly changing behaviour that may threaten local habitats or wildlife, the community (and by extension local decision makers) are more likely to be supportive of rehabilitation efforts.

An example of a newly installed Fluker Post ready to help track environmental change (Source: The Fluker Post Project)

You can see examples of photos from the various Fluker post locations here but you can also keep up to date with various projects at the Fluker Post Facebook page. A relatively new venture has just kicked off using this “technology” to engage with school students – a great idea!

Tracking tidal changes

Another great example of crowd-sourced tracking of the potential environmental change is the Witness King Tides program. The program is coordinated by Green Cross Australia and calls of members of the community to submit photos taken during king tide events (the highest of the spring tides each month) to help generate an indication of what may happen in the future with sea level rise. There is a wonderful collection of photo albums here from across Australia.

This idea of a crowd-sourced collection of photographs tracking tidal events has been tried in the past. Most notable was a collection of photos contributed to by over 250 people taken during a major tide event in 2009. A useful document was produced by NSW Office of Environment and Heritage. It highlights an important issue in relation to potential impacts of sea level rise. The first wave of impacts may not be catastrophic but they will be disruptive.

One of the problems with this method, however, is that these photographs end up being “one offs”. Without a comparison to “normal” conditions, it can sometimes be difficult to gauge the significance of tidal inundation without being familiar with the local area. Fortunately, there are many examples where contributors send both “before” and “after” tidal inundation shots and they do provide a stunning visual representation of the disruption sea level rise may cause. Perhaps the incorporation of “photography points” (following the examples from the Flucker Post or Nerds For Nature teams) at key locations would be a useful addition to the program?

This approach has been adopted bytThe City of Manduarh in Western Australia with their Tidal Image Mandurah Project. The community has been asked to take photos at key locations with a view that images of tidal events such as storm surges, high tide and erosion will help track change. Nothing too fancy in these locations either, just a strategically placed spray painted blue camera!

An example of the spray-painted blue camera on a beachside post inviting members of the community to take and share a photo of Florida Beach (Source: City of Mandurah)

Tracking constructed wetland change

Where would I like to see this implemented? I’ve had the opportunity to work in and around many newly constructed wetlands. These have ranged from small freshwater wetlands in urban areas to extensive rehabilitated estuarine wetlands. The common denominator across all these sites has been vegetation change. I cannot be out there every week taking photos but it would be great if there was a collection of photos being shared by the local communities that I could tap into.

Signage at Gungahlin Wetlands, ACT. An example of structures associated with urban wetlands that can be modified to include opportunities for social media use through the use of recommended hashtags (for Twitter or Instagram) and/or brackets for placing cameras/smartphones

A simple addition of a bracket and details on sharing photographs could easily be incorporated into local signage as it is installed and/or updated. As well as tracking changes in vegetation growth in and around constructed and rehabilitated wetlands, the encroachment of mangroves into mudflats or sandy shores along urban estuaries could be a focus too. Of course, storm events and unusually high tides could be documented too. An added bonus would be if some rare or unusual wildlife popped up in photographs.

Educational signage of this nature is common place around wetlands in Sydney, could the inclusion of some guidelines for social sharing images help track mangrove incursion into shoreline habitats?

There are plenty of other ways social media can assist environmental conservation and rehabilitation. Pozible and Landcare have recently announced the launch (and called for the submission of proposals) of a new global crowdfunding partnership called The Landcare Environment Collection, an opportunity to showcase and support the crowdfunding campaigns of environmental groups in Australia and around the world.

Perhaps I need to prepare a proposal for the installation of some “social sharing” camera stands…

Why not join the conversation on Twitter and help share other examples of where social media could help track environmental change.

With the arrival of mosquito season in North America, health authorities have started issuing warnings about prevention of potentially fatal West Nile virus. My latest coauthored publication reviews the epidemiological and clinical aspects of this mosquito-borne pathogen.

West Nile virus is a pathogen generally spread by mosquitoes from birds to humans. While only about one in five people infected develop symptoms (inc fever, headache, body aches, nausea, vomiting, swollen lymph glands or a skin rash.), for those over 50, there can be more serious implications and the illness may be fatal. There is currently no vaccine, avoiding mosquito bites is the only way to prevent disease.

The virus was first detected in North America in 1999 and has since spread from coast to coast, having a significant impact on the health of both people (resulting in an economic burden of around $56 million per year) and wildlife (particularly birds). Interestingly, from 2007 there was a steady decline in the activity of the virus and many thought that major outbreaks would be a thing of the past but 2012 saw a one of the largest outbreaks in almost a decade. During this time, Texas was particularly hard hit with 1,868 cases and estimated costs of around US$47.6 million.

The activity of the virus in 2013 wasn’t insignificant either.

Annual total numbers of West Nile virus disease cases and deaths reported by CDC 1999-2013.

It is interesting to note that one of the key factors linking outbreaks of West Nile virus in both North America and Europe is the presence of closely related mosquitoes. Unlike dengue, chikungunya or yellow fever viruses that are spread by Aedes mosquitoes, and malaria parasites by Anopheles mosquitoes, West Nile virus is primarily spread by Culex mosquitoes. In particular, the bird-feeding mosquitoes within the Culex pipiens group.

The Culex pipiens group, particularly Culex pipiens, Culex quinquefasciatus and Culex molestus, are closely associated with urban environments. With mosquitoes found in close contact with humans, there is greater risk associated with potential outbreaks.

Our recent review article in the International Journal of General Medicine provides an overview of the clinical and epidemiological aspects of West Nile virus and is a good starting point for anyone interested in this pathogen and the factors that drive outbreaks in North America and Europe.

The abstract of our paper is here:

The reurgence of West Nile virus (WNV) in North America and Europe in recent years has raised the concerns of local authorities and highlighted that mosquito-borne disease is not restricted to tropical regions of the world. WNV is maintained in enzootic cycles involving, primarily, Culex spp. mosquitoes and avian hosts, with epizootic spread to mammals, including horses and humans. Human infection results in symptomatic illness in approximately one-fifth of cases and neuroinvasive disease in less than 1% of infected persons. The most consistently recognized risk factor for neuroinvasive disease is older age, although diabetes mellitus, alcohol excess, and a history of cancer may also increase risk. Despite the increasing public health concern, the current WNV treatments are inadequate. Current evidence supporting the use of ribavirin, interferon α, and WNV-specific immunoglobulin are reviewed. Nucleic acid detection has been an important diagnostic development, which is particularly important for the protection of the donated blood supply. While effective WNV vaccines are widely available for horses, no human vaccine has been registered. Uncertainty surrounds the magnitude of future risk posed by WNV, and predictive models are limited by the heterogeneity of environmental, vector, and host factors, even in neighboring regions. However, recent history has demonstrated that for regions where suitable mosquito vectors and reservoir hosts are present, there will be a risk of major epidemics. Given the potential for these outbreaks to include severe neuroinvasive disease, strategies should be implemented to monitor for, and respond to, outbreak risk. While broadscale mosquito control programs will assist in reducing the abundance of mosquito populations and subsequently reduce the risks of disease, for many individuals, the use of topical insect repellents and other personal protective strategies will remain the first line of defense against infection.